The CD59 Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Raji B lymphoblast cell line, featuring targeted disruption of the CD59 gene. This loss-of-function model enables the study of CD59 function in complement regulation and immune evasion without the constraints of clonal selection, providing a heterogeneous population that reflects natural genetic variability. The polyclonal format is ideal for initial screening and functional assays where population-level phenotypic consistency is sufficient.
The Raji cell line is an Epstein-Barr virus (EBV)-transformed B lymphoblast cell line originally derived from a Burkitt lymphoma. As B lymphocytes, these cells are integral to adaptive immunity and antibody production, and they serve as a robust model for studying B-cell malignancies, lymphomagenesis, and immune cell signaling. The EBV-transformed phenotype confers continuous proliferation in vitro, making Raji cells a practical and widely used host for genetic manipulation and complement biology research.
CD59 is a glycosylphosphatidylinositol (GPI)-anchored glycoprotein that functions as a key inhibitor of the terminal complement pathway. It binds to the C5b-8 complex on cell surfaces, blocking the incorporation and polymerization of C9 and thereby preventing formation of the membrane attack complex (MAC). This protective mechanism shields cells from complement-mediated lysis. The expression of CD59 is regulated by pro-inflammatory cytokines including TNF-alpha, IL-1, and IFN-gamma, as well as the transcription factor Sp1. Downstream, CD59-mediated signaling modulates NF-kB and MAPK pathways, influencing cell survival and immune responses. Interacting partners such as C8, C9, and lipid raft-associated proteins further integrate CD59 within the complement cascade and membrane microdomain organization.
In the Raji B-cell lymphoma context, CD59 expression contributes to the complement resistance often observed in malignant B cells, enabling immune evasion by protecting against antibody-dependent complement-mediated cytotoxicity. Knocking out CD59 in this background provides a powerful system to investigate how the loss of complement regulatory proteins influences tumor cell susceptibility to complement attack, antibody-based therapies, and innate immune recognition. This model is particularly relevant for exploring mechanisms of paroxysmal nocturnal hemoglobinuria (PNH), where CD59 deficiency leads to pathological complement activation, as well as broader roles in autoimmune diseases and cancer.
Researchers can employ these CD59 knockout polyclonal cells in a variety of assays to dissect complement sensitivity and signaling. Complement-dependent cytotoxicity (CDC) assays allow direct measurement of cell lysis in the presence of complement-activating antibodies, while flow cytometry and western blotting confirm CD59 loss and MAC component deposition. Immunofluorescence for C5b-9 or C9 polymerization provides spatial resolution of MAC formation. Cell viability assessments under complement challenge further quantify protective effects. These applications position the CD59 knockout model as an essential tool for drug screening efforts aimed at modulating complement activity or enhancing antibody-dependent cytotoxicity in B-cell malignancies. For further technical details or to inquire about custom modifications, please contact Ascent Research.
